1. Field of the Invention
This invention relates light emitting diode (LED) packages, particularly to the substrate of LED matrix packages.
2. Brief Description of Related Art
FIG. 1 shows a prior art substrate 10 for a LED matrix. On the substrate 10 are first group of printed circuits 11 with bonding pads 11B, and second group of printed circuits 12 with bonding pads 12B. Mounted on the first group of bonding pads 11B are light emitting diodes (LED) 15, each having a bottom electrode and a top electrode. Wire-bonded through wires 14 to the second group of bonding pads 12B are the top electrodes of the LEDs 15. This kind of substrate can only remove the heat generated in the LEDs 15 through the top surface, the bottom surface and the thin side edges. This kind of structure does not remove the heat efficiently.
An object of this invention is to provide efficient heat removal of an LED matrix. Another object of this invention is to increase the reliability of the LED matrix.
These objects are achieved by providing through holes in the substrate for air ventilation or convection. Fans may be used to force the air through these holes and to increase convection.